A mobile crane includes a traveling vehicle body, a slewing base loaded onto a traveling vehicle body, a boom mounted on the slewing base so as to freely perform derricking, and an operator cab provided in the slewing base. During vehicle travel, in which a mobile crane is travelling on an ordinary road, the mobile crane is in a storage state where the boom is contracted and collapsed. In the storage state of the boom, a boom leading end portion protrudes forward from a front end of the traveling vehicle body. Therefore, it is difficult for a worker in the operator cab to confirm the surroundings of the boom leading end portion, particularly sideways.
For example, when the mobile crane enters an intersection, the boom leading end portion enters the intersection earlier than the operator cab. At this time point, it is difficult for the worker in the operator cab to confirm a situation of crossing roads.
PTL 1 discloses a sideways visual recognition apparatus including a camera provided in a boom leading end portion in a state of facing sideways, and a monitor that is provided in an operator cab and displays an image photographed with this camera. In a case of this sideways visual recognition apparatus, even when the operator cab does not enter an intersection, a situation of crossing roads can be confirmed at a time point when the boom leading end portion enters the intersection. Therefore, safety is improved during vehicle travel.